采用干湿周浸实验、失重法和电化学阻抗谱研究了铝合金1060、2A12和7A04在0.02mol/LNaHSO3溶液中的腐蚀行为与规律,用扫描电镜(SEM)观察腐蚀产物形貌,并用能谱仪(EDX)和光电子能谱仪(XPS)分析其组成,并测试力学性能。研究表明,随腐蚀时间的延长,铝合金表面的腐蚀产物不断增多,失重增加,力学性能下降;腐蚀产物形貌以团状为主,并不断向外延伸,呈现不均匀的凹凸形貌;腐蚀产物主要为Al2O3和A1的硫酸盐水合物;电化学阻抗谱拟合结果显示,腐蚀速率先增加后降低,腐蚀时间为360h时腐蚀速率达到最大值;耐蚀性能由强至弱依次为1060,2A12,7A04铝合金。
The corrosion behaviors of aluminium alloys 1060,2A12 and 7A04 under cyclic wet-dry immersion conditions have been investigated in 0.02 mol/L sodium sulfite solution by the mass loss method and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was used to observe the surface morphology; energy dispersive X-ray detector (EDX) and X-ray photoelectron spectroscopy (XPS) were employed to analyze the corrosion products. We also tested the mechanical capability of experimental materials. The results showed that corrosion product was increasing with testing hours prolonging, mass loss adding, strength and elongation percentage declining. Surface observation revealed that corrosion product was agglomerated and accidented, extending forth. The main corrosion product is alumina and aluminium sulfate hydrate. The results of EIS indicated that corrosion rate is highest in 360 hour. Corrosion resistance of aluminium 1060 was best in 0.02 mol/L sodium sulfite solution, but that of aluminium alloy 7A04 was worst.